The present invention relates to an electric-motor-and-pump assembly including an electric motor having a pump-sided shaft end which extends through a housing lid, is supported with at least one roller bearing on a pump housing, and whose purpose is to drive pump pistons, wherein the housing lid in the area of the shaft passage leaves open a gap which connects a pump-sided crank chamber to an inside space of the motor.
DE-OS 43 15 826 discloses an electric-motor-and-pump assembly of this type. It may occur in operation of this assembly that a part of the pressure fluid being pumped propagates as a so-called leakage fluid into a pump-sided crank chamber and from there through a gap between the pump housing and the motor housing into the interior of the motor. The pressure fluid which inadvertently entered the area of the rotor may cause short-circuits and, thus, malfunctions of the motor.
Therefore, an object of the present invention is to protect the electric motor of an electric-motor-and-pump assembly against the inadvertent ingress of leakage fluids in an inexpensive fashion. Another object of the present invention includes minimizing the overall axial dimensions of the assembly because small-size assemblies are preferred especially in the automotive field.